Analysis of Water Pollution Trend in Zhaoyuan Section of Songhua River

Based on data analysis and variational curve of NH_3-N and IMn,two synthetic pollution index monitored by Zhaoyuan Environmental Monitoring Station for five successive years,the author points out that in recent years,the exploitation of oil field along the river and on the grassed islands has resulted in new pollution sources to Songhua River besides the influence of old pollution sources from chemical industry enterprises in Jilin Province.So,close attention should be given to the prevention of the worse of organic pollution in the upper reach of Songhua River.